2/2 CONNECTICUT EXPERIMENT STATION REPORT, 1901. 



it, red spider was killed. But it is well nigh impossible to 

 thoroughly cover thick-growing plants, so some lived to per- 

 petuate the pest in the house. Later the plants were given a 

 careful spraying once each week, and red spider was kept in 

 check nicely even where it had thoroughly infested the plants. 

 Lice and Aleyrodes were readily killed by the mixture, which 

 is not only easily prepared but lacks the disagreeable odor 

 peculiar to many insecticides, especially whale-oil soap and 

 tobacco water. 



As the soap does not dissolve readily in cold water, the best 

 method is to cut the soap in thin slices and dissolve in boiling 

 water, then add enough cold water to make the right propor- 

 tions. The mixture thickens to a jelly-like substance on cool- 

 ing and must therefore be applied warm. It may be sprayed 

 upon the plants, or small potted plants may be dipped into a 

 pailful of the mixture. 



Bars of fresh "Ivory" soap were found to have an average 

 weight, exclusive of the wrapper, of 258 grams, or about 9 

 ounces, while the small size weighed 152 grams, or 5.3 ounces. 

 Thus in common practice, the soap need not be weighed nor the 

 water measured, but half of a cake of laundry size or four- 

 fifths of a small-sized cake will answer for a pailful. The 

 common-sized pail holds two and one-half gallons when filled 

 to the brim, but it cannot be conveniently carried if charged 

 with more than two gallons. 



"Welcome" soap was next given a trial and found to be fully 

 as effective as "Ivory" when dissolved in the same proportions, 

 and to dissolve somewhat more readily. It does not thicken as 

 quickly on cooling. The bar of laundry-size weighs 317 grams, 

 or about n ounces. One of these cakes may therefore be 

 divided into three pieces and each dissolved in a pail of water. 



The tomato house has each winter for several years been 

 infested with white fly (Aleyrodes vaporariorum West.) and 

 many remedies have been used, none of which have proved more 

 effective than soap and water. Fir-tree oil was equally so, but 

 is too expensive for general use. The tomato plants were 

 sprayed about every week for three months with "Welcome" 

 soap dissolved in water at the rate of one pound in 8 gallons. 

 The spray seemed to kill all larvae and adults with which it came 

 in contact. During the operation many adults fly from the 

 plants, but are hit by the spray when in mid-air and killed. 



